High voltage rectifier or inverter



Jan. 9, 1940.

'J. SLEPIAN HIGH VOLTAGE RECTIFIER OR INVERTER Filed Nov. 24, 1957WITNESSES: I

RM Y. a N R WY 0 mbjvm J m Patented Jan. 9, 1940 PATENT. OFFI E HIGHVOLTAGEBIECTIFIER OR INVERTER Joseph Slcpian, Pittsburgh, Pa., assignorto- Westv inghouse Electric &: Manufacturing Company, m East Pittsburgh,Pa=., a corporation of Pennsyl vania ApplicationNovember 24, 1937,Serial No. 176,261

12 Claims. (c1: 250 27.5) I My invention relates to electricdischargedevices, and particularly to high voltage rectifiers orinverters. v An object of my invention is to provide a discharge devicefor heavy duty having reliable operation and freedom from backfires.

' Other objects and advantages of the invention will be apparent fromthe following description and drawing, in which the single'figure is across 'sectional view illustrating a preferred embodiment of myinvention.

In particular my invention contemplates utilizing a blast of ionizedvapor to establish the arc to the anode and likewise contemplatesutilizing 'ablast of fresh un-ionized vapor to extinguish the arcand toinsure that there are no backfires. In the figure is disclosed a casingll) of the metallic type having an anode ll therein insulated from thecasing by any suitable insulation 2.0 such as l2 sealed to both theanode and the casing. This anode is preferably cooled by a medium suchas the liquid l3 illustrated, which passes through the inlet l4 and theoutlet Hi. In the bottom portion of the casing is a liquid cathode 16such as mercury. The interior of the casing has a gaseous atmosphere atpreferably several atmospheres pressure, preferably by means of a gassuch as argon, helium or hydrogen.

I prefer to restrict the striking area on the liquid cathode exposed tothe anode and for such restriction I prefer to utilize insulating means.ll having a funnel shaped throat or hollow portion l8 extending towardsthe liquid cathode surface and preferably extending below the surfacetherea of. The insulating means may also have an extended surface l9 tonormally prevent the arc from striking other portions of the liquidcathode except for the bottom portion 20 in the throat l8.

In order to establish the arc, I utilize a make- 40 alive 2! constructedofhigh resistance material such as boron carbide and having a portionimmersed into the liquid mercury. The connection 22 extends through theliquid cathode and casing by means of any suitable insulation 23. This45 make-alive electrode 2| is more particularly described in Patent No.2,069,283, issued February 2 1937, to L. R. Ludwig and myself as jointinventors. The make-alive is so connected as described in this patentthat a cathode spot is cre- 50 ated on the mercury surface adjacent themakealive at the beginning of the conductive portion of each cycle ofalternating or pulsating current.

I prefer to have an extension 24 extending over the make-alive which isplaced at one side of the 55 throat N3 of the refractory insulatingmeans H in order to protect, the make-alive from the direct arc pathfrom thean'ode to the exposed surface 20 of the liquidcathode and alsofor the purpose of further restricting the throatlB'.

In operation a cathode spot is formed at the surface of the mercurycathode at '20 and the mercury boils vigorously, thus producing a strongblast of mercury vapor at several atmospheres pressure. This strongblast of mercury vapor will carry the are which was struck to themakealive up to the anode l l and establish the break down of the tube.When' it is desired'that the tube stop operating,'the current to themake alive is cut off and when the current comes to zero, the boiling ofthe mercury at the surface 26 will carry a fresh'bla'st of un-ionizedvapor that extinguishes and prevents the reignition of the arc. Becauseof the fact that a strongblast of vapor is always travelling up in thethroat, there will be no tendency for the arc to backfire against 30this blast.

My invention, accordingly, provides a very reliable structure for veryheavy duty. It is apparent, however, that many modifications may be madein the preferred embodiment which I have disclosed without departingfrom the spirit of the invention, and, accordingly, I desire only suchlimitations on the following claims as are necessituated by the priorart.

I claim as my invention: 30

1. An electric discharge device comprising a casing having a mercurycathode, an anode, stationary funnel shaped insulating means at thesurface of the mercury cathodehaving its wideropen end facing said anodeand stationary means 35 for igniting an are at the surface of saidmercury cathode within said funnel shaped insulating means.

2. An electric discharge device comprising a casing having a gaseousatmosphere of several at- 40 mospheres, a mercury cathode, an anode,funnel shapedinsulating means at the-surface of the mercury cathode andmeans for igniting an are at the surface of said mercury'cathode withinsaid funnel shaped insulating means.

3. An electric discharge devicecomprising a casing having a mercurycathode, an anode, funnel shaped insulating means at the surface of themercury cathode having its wider-open end facing said anode and meansfor creating a new cathode spot at the beginning of each conductingportion of the cycle of current within the funnel shaped portion ofsaidinsulating means. 7

4. An electric discharge device comprising a casing having a mercurycathode, an anode, fun- 66 nel shaped insulating means at the surface ofthe mercury cathode having its wider-open end facing said anode and.means for creating a new cathode spot at the beginning of eachconducting portion of the cycle of current within the funnel shapedportion of said insulating means, said insulating means having a portionprotecting said cathode spot creating means from the direct arc betweensaid anode and cathode.

5. An electric discharge device comprising a casing having a gaseousatmosphere at several atmospheres pressure, an anode and a liquidcathode therein, tubular insulating means forming a restricted columnextending above the surface of the liquid cathode and means for creatinga cathode spot at the surface of the liquid cathode at the base of saidrestricted column.

6. An electric discharge device comprising a casing having a gaseousatmosphere at several atmospheres pressure, an anode and a liquidcathode therein, tubular insulating means forming a restricted columnextending above the surface of the liquid cathode and means for creatinga cathode spot at the surface of the liquid cathode at the base of saidrestricted column, said last mentioned means being protected from thedirect are between said anode and cathode.

'7. A vacuum-tight container enclosing an v anode and a vaporizablecathode, an unobstructed straight path from said cathode to said anode,

means to intermittently excite said cathode, guide walls near thesurface of said cathode for directing the vapor produced by saidexcitation toward said anode.

8. A vacuum-tight container enclosing an anode and a vaporizablecathode, means to intermittently excite said cathode, guide walls nearthe surface of said cathode for directing the vapor produced by saidexcitation toward said anode, a gaseous atmosphere of a pressure greaterthan an atmosphere within said container.

9. A vacuum-tight container enclosing an anode and a vaporizablecathode, means tointermittently excite said cathode, guide walls nearthe surface of said cathode for directing the vapor produced by saidexcitation toward said anode, a shield covering the surface of saidcathode outside the path of said vapor.

10. A vacuum-tight container enclosing an anode and a vaporizablecathode, means to intermittently excite said cathode, guide walls nearthe surface of said cathode for directing the vapor produced by saidexcitation toward said anode, a shield covering the surface of saidcathode outside the path of said vapor, a gaseous atmosphere of apressure greater than an atmosphere within said container.

11. A vacuum-tight container enclosing an anode and a vaporizablecathode, an igniter electrode acting to intermittently excite a spot onsaid cathode, guide walls near the surface of said cathode for directingthe vapor produced by said excitation toward said anode, and meanstending to produce flow of pulsating current between said anode andcathode.

12. A vacuum-tight container enclosing an anode and a vaporizablecathode, an igniter electrode acting to intermittently excite a spot onsaid cathode, guide walls near the surface of said cathode for directingthe vapor produced by said excitation toward said anode, and a gaseousatmosphere of a pressure greater than one atmosphere in said container.

JOSEPH SLEPIAN.

